Partial cDNA sequence of a relaxin‐like factor (RLF) receptor,LGR8 and possible existence of the RLF ligand‐receptor system in goat testes

Relaxin‐like factor (RLF), also known as insulin‐like factor 3 (INSL3), is produced by testicular Leydig cells, but its specific receptor LGR8 (leucine‐rich repeat family of G‐protein‐coupled receptor 8) has not been identified in goats. This study aimed to identify complementary DNA (cDNA) sequences of goat LGR8, and characterize the expression of both RLF and LGR8 in goat testes by RT‐PCR and immunohistochemistry. Testes were collected from immature (3‐month‐old) and mature (24‐month‐old) Saanen goats, and partial cDNA sequences of the goat homologue of human LGR8 were identified. The sequence encoded a reduced peptide sequence of 167 amino acids, which corresponded to transmembrane regions 2 through 5, followed by the beginning of intracellular loop 3 of human LGR8. Expression of both LGR8 and RLF genes was drastically increased in mature testes compared with immature ones. Although RLF protein was restricted to Leydig cells, LGR8 protein was detected in both Leydig cells and seminiferous epithelial cells (possibly germ cells and Sertoli cells). These results reveal a possible existence of the RLF‐LGR8 ligand‐receptor system within the goat testis, suggesting that RLF may play a role in testicular function through LGR8 on Leydig cells and seminiferous epithelial cells in an autocrine and/or paracrine manner.     

Complete nucleotide sequence of mitochondrial DNA in White Leghorn and White Plymouth Rock chickens

Among the chicken breeds, White Leghorn (WL) and White Plymouth Rock (WR) are major breeds and have different history in their establishments. Whole mitochondrial DNA of the breeds were sequenced in order to elucidate the genetic relationship between the breeds. The lengths of the two WL and two WR mitochondrial DNA were found to be 16 788 and 16 785 base pairs, respectively. When the DNA sequences were compared, the similarity was found to be 99.96% (six nucleotide differences). In addition, the present study conformed the existence of an extra nucleotide ‘C’ in NADH dehydrogenase subunit 3 (ND3) of the chicken mitochondrial DNA, which has been consistently observed in Galliformes.     

Expression analysis of the type I keratin protein keratin 33A in goat coat hair

The coat of a goat, like that of many mammalian species, consists of an outer coat of coarse hairs and an under coat of fine, downy hairs. The coarse guard hairs are produced by primary follicles and the finer cashmere hairs by secondary follicles. We previously reported that hair keratins are components of cashmere hair, and proteomic analysis revealed that their expression is elevated in winter coat hair. To determine detailed characterization, we have cloned keratin 33A gene, a major highly expressed keratin in winter, and then analyzed the expression of goat hair coat. By Western analysis, we detected that keratin 33A protein is expressed only in hair coat among the various goat tissues. Moreover, the expression level in winter has increased in cashmere high‐producing Korean native breed, whereas the expression levels between summer and winter had not changed in cashmere low‐producing Saanen. In addition, by immunohistochemistry we determined that keratin 33A is localized in the major cortex portion of cashmere fiber. These results confirm that keratin 33A is a structural protein of goat cashmere hair fiber.     

Molecular phylogeny and diversity of Myanmar and Bhutan mithun based on mtDNA sequences

The mithun (Bos frontalis), synonymous with mithan and gayal, is considered to be a domesticated form of gaur (B. gaurus). However, there has been a controversy concerning its origin. In an effort to address this issue, the mitochondrial cytochrome b (cytb) genes of 20 mithun from Myanmar and 13 from Bhutan were sequenced to trace its maternal origin. Seven cytb haplotypes were found in the 33 mithun, and the phylogenetic tree for these haplotypes clearly showed three embranchments involving five gaur types, a B. indicus type, and a B. taurus type. Sixteen Myanmar and 12 Bhutan mithun had gaur haplotypes, while a B. indicus haplotype was found in three Myanmar and one Bhutan mithun. The B. taurus haplotype was detected in a single Myanmar animal. These results demonstrated that the principal maternal origin of mithun was gaur and suggested that it was directly domesticated from gaur. However, some introgression of domestic cattle existed in current mithun populations. The presence of cattle mtDNA raised the question of how many cattle nuclear genes might have been integrated into the gene pool of mithun.     

Clay minerals of red-yellow soils derived from pleistocene sediments in Japan

Red-Yellow soils are widely developed on terraces and hilly lands in the south-western half of Japan. They do not show any evidence of bleaching in the lower part of the A horizon, and are characterized by an extremely strong acid reaction, and a very low base-status⁹⁾. There are few studies on clay mineralogy of Red-Yellow soils in Japan. Egawa et al⁴⁾. have reported on clay mineralogy of soils derived from the Pleistocene and the Tertiary sediments most of which may be regarded as Red-Yellow soils. Matsui and Katô¹⁰⁾ have described clay minerals of Red-Yellow soils derived from the Pleistocene sediment in the environs of Shinjobara, Shizuoka Prefecture. These investigations indicated that clay minerals of Red-Yellow soils derived from the Pleistocene sediments consisted mainly of kaolin minerals, whereas those of Red-Yell ow soils derived from the Tertiary sediments were of the kaolin-illite association.     

Kazakhstani native cattle reveal highly divergent mtDNA from Bos taurus and Bos indicus lineages with an absence of Bos indicus Y chromosome

Kazakhstan is the largest landlocked country and contains two important propagation routes for livestock from the Fertile Crescent to Asia. Therefore, genetic information about Kazakhstani cattle can be important for understanding the propagation history and the genetic admixture in Central Asian cattle. In the present study, we analyzed the complete mtDNA D‐loop sequence and SRY gene polymorphism in 122 Kazakhstani native cattle. The D‐loop sequences revealed 79 mitochondrial haplotypes, with the major haplogroups T and I. The Bos taurus subhaplogroups consisted of T (3.3%), T1 (2.5%), T2 (2.5%), and T4 (0.8%) in addition to the predominant subhaplogroup T3 (86.9%), and the Bos indicus subhaplogroup of I1 (4.1%). Subsequently, we investigated the paternal lineages of Bos taurus and Bos indicus, however, all Kazakhstani cattle were shown to have Y chromosome of Bos taurus origin. While highly divergent mtDNA subhaplogroups in Kazakhstani cattle could be due to the geographical proximity of Kazakhstan with the domestication center of the Fertile Crescent, the absence of Bos indicus Y chromosomes could be explained by a decoupling of the introgression dynamics of maternal and paternal lineages. This genetic information would contribute to understanding the genetic diversity and propagation history of cattle in Central Asia.